Lung reduction system

ABSTRACT

A long term oxygen therapy system having an oxygen supply directly linked with a patient&#39;s lung or lungs may be utilized to more efficiently treat hypoxia caused by chronic obstructive pulmonary disease such as emphysema and chronic bronchitis. The system includes an oxygen source, one or more valves and fluid carrying conduits. The fluid carrying conduits link the oxygen source to diseased sites within the patients lungs. A collateral ventilation bypass trap system directly linked with a patient&#39;s lung or lungs may be utilized to increase the expiratory flow from the diseased lung or lungs, thereby treating another aspect of chronic obstructive pulmonary disease. The system includes a trap, a filter/one-way valve and an air carrying conduit. In various embodiments, the system may be intrathoracic, extrathoracic or a combination thereof. A pulmonary decompression device may also be utilized to remove trapped air in the lung or lungs, thereby reducing the volume of diseased lung tissue. A lung reduction device may passively decompress the lung or lungs. In order for the system to be effective, an airtight seal between the parietal and visceral pleurae is required. Chemical pleurodesis is utilized for creating the seal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Provisional Application No.60/475,291 filed Jun. 3, 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to systems and methods for removingtrapped air in emphysematous lungs, and more particularly, to systemsand methods for removing trapped air in emphysematous hyperinflatedlungs by bypassing non-patent airways via a conduit through the outerpleural layer of the lung to a containment/trap device. The presentinvention also relates to a collateral ventilation bypass system thatutilizes the trachea for expelling trapped air rather than acontainment/trap device. The present invention also relates to a deviceand methodology to assist in pulmonary decompression andnon-surgical/resection lung volume reduction. The present invention alsorelates to systems and methods for chemical pleurodesis.

2. Discussion of the Related Art

As a result of studies that date back to the 1930's and particularlystudies conducted in the 1960's and early 1970's, it has been determinedthat long-term continuous oxygen therapy is beneficial in the treatmentof hypoxemic patients with chronic obstructive pulmonary disease. Inother words, a patient's life and quality of life can be improved byproviding a constant supplemental supply of oxygen to the patient'slungs.

However, with the desire to contain medical costs, there is a growingconcern that the additional cost of providing continuous oxygen therapyfor chronic lung disease will create an excessive increase in the annualcost of oxygen therapy. Thus, it is desirable that oxygen therapy, whenprovided, be as cost effective as possible.

The standard treatment for patients requiring supplemental oxygen isstill to deliver oxygen from an oxygen source by means of a nasalcannula. Such treatment, however, requires a large amount of oxygen,which is wasteful and can cause soreness and irritation to the nose, aswell as being potentially aggravating. Other undesirable effects havealso been reported. Various other medical approaches which have beenproposed to help reduce the cost of continuous oxygen therapy have beenstudied.

Various devices and methods have been devised for performing emergencycricothyroidotomies and for providing a tracheotomy tube so that apatient whose airway is otherwise blocked may continue to breath. Suchdevices are generally intended only for use with a patient who is notbreathing spontaneously and are not suitable for the long term treatmentof chronic lung disease. Typically, such devices are installed bypuncturing the skin to create a hole into the cricoid membrane of thelarynx above the trachea into which a relatively large curvedtracheotomy tube is inserted. As previously described, the use of suchtubes has been restricted medically to emergency situations where thepatient would otherwise suffocate due to the blockage of the airway.Such emergency tracheotomy tubes are not suitable for long term therapyafter the airway blockage is removed.

Other devices which have been found satisfactory for emergency orventilator use are described in U.S. Pat. Nos. 953,922 to Rogers;2,873,742 to Shelden; 3,384,087 to Brummelkamp; 3,511,243 to Toy;3,556,103 to Calhoun; 2,991,787 to Shelden, et al. 3,688,773 to Weiss;3,817,250 to Weiss, et al.; and 3,916,903 to Pozzi.

Although tracheotomy tubes are satisfactory for their intended purpose,they are not intended for chronic usage by outpatients as a means fordelivering supplemental oxygen to spontaneously breathing patients withchronic obstructive pulmonary disease. Such tracheotomy tubes aregenerally designed so as to provide the total air supply to the patientfor a relatively short period of time. The tracheotomy tubes aregenerally of rigid or semi-rigid construction and of caliber rangingfrom 2.5 mm outside diameter in infants to 15 mm outside diameter inadults. They are normally inserted in an operating room as a surgicalprocedure or during emergency situations, through the crico-thyroidmembrane where the tissue is less vascular and the possibility ofbleeding is reduced. These devices are intended to permit passage of airin both directions until normal breathing has been restored by othermeans.

Another type of tracheotomy tube is disclosed in Jacobs, U.S. Pat. Nos.3,682,166 and 3,788,326. The catheter described therein is placed over14 or 16 gauge needle and inserted through the crico-thyroid membranefor supplying air or oxygen and vacuum on an emergency basis to restorethe breathing of a non-breathing patient. The air or oxygen is suppliedat 30 to 100 psi for inflation and deflation of the patient's lungs. TheJacobs catheter, like the other tracheotomy tubes previously used, isnot suitable for long term outpatient use, and could not easily beadapted to such use.

Due to the limited functionality of tracheotomy tubes, transtrachealcatheters have been proposed and used for long term supplemental oxygentherapy. For example the small diameter transtracheal catheter (16gauge) developed by Dr. Henry J. Heimlich (described in THE ANNALS OFOTOLOGY, RHINOLOGY & LARYNGOLOGY, November-December 1982; RespiratoryRehabilitation with Transtracheal Oxygen System) has been used by theinsertion of a relatively large cutting needle (14 gauge) into thetrachea at the mid-point between the cricothyroid membrane and thesternal notch. This catheter size can supply oxygen up to about 3 litersper minute at low pressures, such as 2 psi which may be insufficient forpatients who require higher flow rates. It does not, however, lenditself to outpatient use and maintenance, such as periodic removal andcleaning, primarily because the connector between the catheter and theoxygen supply hose is adjacent and against the anterior portion of thetrachea and cannot be easily seen and manipulated by the patient.Furthermore, the catheter is not provided with positive means to protectagainst kinking or collapsing which would prevent its effective use onan outpatient basis. Such a feature is not only desirable but necessaryfor long term outpatient and home care use. Also, because of itsstructure, i.e. only one exit opening, the oxygen from the catheter isdirected straight down the trachea toward the bifurcation between thebronchi. Because of the normal anatomy of the bronchi wherein the leftbronchus is at a more acute angle to the trachea than the rightbronchus, more of the oxygen from that catheter tends to be directedinto the right bronchus rather than being directed or mixed for moreequal utilization by both bronchi. Also, as structured, the oxygen canstrike the carina, resulting in an undesirable tickling sensation andcough. In addition, in such devices, if a substantial portion of theoxygen is directed against the back wall of the trachea causing erosionof the mucosa in this area which may cause chapping and bleeding.Overall, because of the limited output from the device, it may notoperate to supply sufficient supplemental oxygen when the patient isexercising or otherwise quite active or has severe disease.

Diseases associated with chronic obstructive pulmonary disease includechronic bronchitis and emphysema. One aspect of an emphysematous lung isthat the communicating flow of air between neighboring air sacs is muchmore prevalent as compared to healthy lungs. This phenomenon is known ascollateral ventilation. Another aspect of an emphysematous lung is thatair cannot be expelled from the native airways due to the loss of tissueelastic recoil and radial support of the airways. Essentially, the lossof elastic recoil of the lung tissue contributes to the inability ofindividuals to exhale completely. The loss of radial support of theairways also allows a collapsing phenomenon to occur during theexpiratory phase of breathing. This collapsing phenomenon alsointensifies the inability for individuals to exhale completely. As theinability to exhale completely increases, residual volume in the lungsalso increases. This then causes the lung to establish in ahyperinflated state where an individual can only take short shallowbreaths. Essentially, air is not effectively expelled and stale airaccumulates in the lungs. Once the stale air accumulates in the lungs,the individual is deprived of oxygen.

Currently, treatments for chronic obstructive pulmonary disease includebronchodilating drugs, oxygen therapy as described above, and lungvolume reduction surgery. Bronchodilating drugs only work on apercentage of patients with chronic obstructive pulmonary disease andgenerally only provides short term relief. Oxygen therapy is impracticalfor the reasons described above, and lung volume reduction surgery is anextremely traumatic procedure that involves removing part of the lung.The long term benefits of lung volume reduction surgery are not fullyknown.

Accordingly, there exists a need for increasing the expiratory flow froman individual suffering from chronic obstructive pulmonary disease. Inaddition, there exists a need for a minimally invasive means forremoving trapped air from the lung or lungs that would allow healthylung tissue to better ventilate. There also exists a need for aminimally invasive means for allowing trapped air from the lung or lungsto escape that would allow healthy lung tissue to better ventilate

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages associated withtreating chronic obstructive pulmonary disease, as briefly describedabove, by utilizing the phenomenon of collateral ventilation to increasethe expiratory flow from a diseased lung. The present invention alsoprovides a means for assisting in or facilitating pulmonarydecompression to compress the diseased area or area of the lung or lungsto a smaller volume.

In accordance with a first aspect, the present invention is directed toa lung reduction device. The device comprising at least one first memberin fluid communication, at a predetermine site, within a lung of apatient, a sealing device for establishing an airtight seal between theat least one first member and the lung, and a second member connected tothe at least one first member, the second member comprising an apparatusfor allowing air from the lung of the patient to vent to an areaexternal of the lung and preventing air from an area external of thelung from re-entering the lung through the device.

In accordance with a second aspect, the present invention is directed toa lung reduction device. The device comprising at least one first memberin fluid communication, at a predetermined site, within a lung of apatient, a first sealing device for establishing an airtight sealbetween the at least one first member and the lung, a second memberconnected to and in fluid communication with the at least one firstmember, the second member comprising an apparatus for allowing air fromthe lung of the patient to vent to the ambient environment, andpreventing air from the ambient environment from re-entering the lungthrough the device, the second member including a section positionedexternal of the body of the patient, and a second sealing device forsealing the section positioned external of the body of the patient tothe body.

In accordance with a third aspect, the present invention is directed toa method for reducing the volume of a hyperinflated portion of a lung ofa patient. The device comprising determining a site of hyperinflation ina patient's lung, and allowing air from the hyperinflated portion of thelung to vent through a device to the ambient environment and preventingair from the ambient environment from re-entering the lung through thedevice.

The long-term oxygen therapy system of the present invention deliversoxygen directly to diseased sites in a patient's lungs. Long term oxygentherapy is widely accepted as the standard treatment for hypoxia causedby chronic obstructive pulmonary disease, for example, pulmonaryemphysema. Pulmonary emphysema is a chronic obstructive pulmonarydisease wherein the alveoli of the lungs lose their elasticity and thewalls between adjacent alveoli are destroyed. As more and more alveoliwalls are lost, the air exchange surface area of the lungs is reduceduntil air exchange becomes seriously impaired. The combination of mucushypersecretion and dynamic air compression is a mechanism of airflowlimitation in chronic obstructive pulmonary disease. Dynamic aircompression results from the loss of tethering forces exerted on theairway due to the reduction in lung tissue elasticity. Essentially,stale air accumulates in the lungs, thereby depriving the individual ofoxygen. Various methods may be utilized to determine the location orlocations of the diseased tissue, for example, computerized axialtomography or CAT scans, magnetic resonance imaging or MRI, positronemission tomograph or PET, and/or standard X-ray imaging. Once thelocation or locations of the diseased tissue are located, anastomoticopenings are made in the thoracic cavity and lung or lungs and one ormore oxygen carrying conduits are positioned and sealed therein. The oneor more oxygen carrying conduits are connected to an oxygen source whichsupplies oxygen under elevated pressure directly to the diseased portionor portions of the lung or lungs. The pressurized oxygen essentiallydisplaces the accumulated air and is thus more easily absorbed by thealveoli tissue. In addition, the long term oxygen therapy system may beconfigured in such a way as to provide collateral ventilation bypass inaddition to direct oxygen therapy. In this configuration, an additionalconduit may be connected between the main conduit and the individual'strachea with the appropriate valve arrangement. In this configuration,stale air may be removed through the trachea when the individual exhalessince the trachea is directly linked with the diseased site or sites inthe lung via the conduits.

The long term oxygen therapy system of the present invention improvesoxygen transfer efficiency in the lungs thereby reducing oxygen supplyrequirements, which in turn reduces the patient's medical costs. Thesystem also allows for improved self-image, improved mobility, greaterexercise capability and is easily maintained.

The above-described long term oxygen therapy system may be utilized toeffectively treat hypoxia caused by chronic obstructive pulmonarydisease; however, other means may be desirable to treat other aspects ofthe disease. As set forth above, emphysema is distinguished asirreversible damage to lung tissue. The breakdown of lung tissue leadsto the reduced ability for the lungs to recoil. The tissue breakdownalso leads to the loss of radial support of the airways. Consequently,the loss of elastic recoil of the lung tissue contributes to theinability for individuals with emphysema to exhale completely. The lossof radial support of the airways also allows a collapsing phenomenon tooccur during the expiratory phase of breathing. This collapsingphenomenon also intensifies the inability for individuals to exhalecompletely. As the inability to exhale increases, residual volume in thelungs also increases. This then causes the lung to establish in ahyperinflated state wherein an individual can only take short shallowbreaths.

The collateral ventilation bypass trap system of the present inventionutilizes the above-described collateral ventilation phenomenon toincrease the expiratory flow from a diseased lung or lungs, therebytreating another aspect of chronic obstructive pulmonary disease.Essentially, the most collaterally ventilated area of the lung or lungsis determined utilizing the scanning techniques described above. Oncethis area or areas are located, a conduit or conduits are positioned ina passage or passages that access the outer pleural layer of thediseased lung or lungs. The conduit or conduits utilize the collateralventilation of the lung or lungs and allow the entrapped air to bypassthe native airways and be expelled to a containment system outside ofthe body.

In an alternate embodiment, the trachea, or other proximal airways,including the bronchus, may be utilized for expelling trapped air ratherthan a containment/trap device.

The pulmonary decompression device of the present invention removes airfrom hyperinflated regions of the lung or lungs of a patient by creatinga slight pressure differential between the internal volume of the lungand a location external of the lung. An apparatus such as a vacuum fanor pump creates the pressure differential, thereby removing the trappedair and reducing the volume of diseased tissue.

The lung reduction device of the present invention allows trapped airfrom hyperinflated regions of the lung or lungs of a patient to vent tothe external environment through a one-way valve. The valve prevents airfrom flowing back into the lung or lungs.

In order for the system to be effective, the components of the systemare preferably sealed to the lung. Accordingly, the localizedpleurodesis chemical delivery system of the present invention isutilized to create a pleurodesis in the area or areas of the lung thatare most collaterally ventilated. Various chemicals, agents and/orcompounds may be delivered via catheter based delivery systems or viaimplantable medical devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention will beapparent from the following, more particular description of preferredembodiments of the invention, as illustrated in the accompanyingdrawings.

FIG. 1 is a diagrammatic representation of a first exemplary embodimentof the long term oxygen therapy system in accordance with the presentinvention.

FIG. 2 is a diagrammatic representation of a first exemplary embodimentof a sealing device utilized in conjunction with the long term oxygentherapy system of the present invention.

FIG. 3 is a diagrammatic representation of a second exemplary embodimentof a sealing device utilized in conjunction with the long term oxygentherapy system of the present invention.

FIG. 4 is a diagrammatic representation of a third exemplary embodimentof a sealing device utilized in conjunction with the long term oxygentherapy system of the present invention.

FIG. 5 is a diagrammatic representation of a fourth exemplary embodimentof a sealing device utilized in conjunction with the long term oxygentherapy system of the present invention.

FIG. 6 is a diagrammatic representation of a second exemplary embodimentof the long term oxygen therapy system in accordance with the presentinvention.

FIG. 7 is a diagrammatic representation of a first exemplary embodimentof a collateral ventilation bypass trap system in accordance with thepresent invention.

FIG. 8 is a diagrammatic representation of a second exemplary embodimentof a collateral ventilation bypass system in accordance with the presentinvention.

FIG. 9 is a diagrammatic representation of a third exemplary embodimentof a collateral ventilation bypass system in accordance with the presentinvention.

FIG. 10 is a diagrammatic representation of a fourth exemplaryembodiment of a collateral ventilation bypass system in accordance withthe present invention.

FIG. 11 is a diagrammatic representation of an exemplary pulmonarydecompression device in accordance with the present invention.

FIGS. 12 a and 12 b are diagrammatic representations of the effects onlung volume in accordance with the present invention.

FIGS. 13 a and 13 b are diagrammatic representations of the effects onlung volume reduction utilizing the lung reduction system in accordancewith the present invention.

FIG. 14 is a diagrammatic representation of a first exemplary embodimentof a localized pleurodesis chemical delivery system.

FIG. 15 is a diagrammatic representation of a second exemplaryembodiment of a localized pleurodesis chemical delivery system.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Air typically enters the mammalian body through the nostrils and flowsinto the nasal cavities. As the air passes through the nostrils andnasal cavities, it is filtered, moistened and raised or lowered toapproximately body temperature. The back of the nasal cavities iscontinuous with the pharynx (throat region); therefore, air may reachthe pharynx from the nasal cavities or from the mouth. Accordingly, ifequipped, the mammal may breath through its nose or mouth. Generally airfrom the mouth is not as filtered or temperature regulated as air fromthe nostrils. The air in the pharynx flows from an opening in the floorof the pharynx and into the larynx (voice box). The epiglottisautomatically closes off the larynx during swallowing so that solidsand/or liquids enter the esophagus rather than the lower air passagewaysor airways. From the larynx, the air passes into the trachea, whichdivides into two branches, referred to as the bronchi. The bronchi areconnected to the lungs.

The lungs are large, paired, spongy, elastic organs, which arepositioned in the thoracic cavity. The lungs are in contact with thewalls of the thoracic cavity. In humans, the right lung comprises threelobes and the left lung comprises two lobes. Lungs are paired in allmammals, but the number of lobes or sections of lungs varies from mammalto mammal. Healthy lungs, as discussed below, have a tremendous surfacearea for gas/air exchange. Both the left and right lung is covered witha pleural membrane. Essentially, the pleural membrane around each lungforms a continuous sac that encloses the lung. A pleural membrane alsoforms a lining for the thoracic cavity. The space between the pleuralmembrane forming the lining of the thoracic cavity and the pleuralmembranes enclosing the lungs is referred to as the pleural cavity. Thepleural cavity comprises a film of fluid that serves as a lubricantbetween the lungs and the chest wall.

In the lungs, the bronchi branch into a multiplicity of smaller vesselsreferred to as bronchioles. Typically, there are more than one millionbronchioles in each lung. Each bronchiole ends in a cluster of extremelysmall air sacs referred to as alveoli. An extremely thin, single layerof epithelial cells lining each alveolus wall and an extremely thin,single layer of epithelial cells lining the capillary walls separate theair/gas in the alveolus from the blood. Oxygen molecules in higherconcentration pass by simple diffusion through the two thin layers fromthe alveoli into the blood in the pulmonary capillaries. Simultaneously,carbon dioxide molecules in higher concentration pass by simplediffusion through the two thin layers from the blood in the pulmonarycapillaries into the alveoli.

Breathing is a mechanical process involving inspiration and expiration.The thoracic cavity is normally a closed system and air cannot enter orleave the lungs except through the trachea. If the chest wall is somehowcompromised and air/gas enters the pleural cavity, the lungs willtypically collapse. When the volume of the thoracic cavity is increasedby the contraction of the diaphragm, the volume of the lungs is alsoincreased. As the volume of the lungs increase, the pressure of the airin the lungs falls slightly below the pressure of the air external tothe body (ambient air pressure). Accordingly, as a result of this slightpressure differential, external or ambient air flows through therespiratory passageways described above and fills the lungs until thepressure equalizes. This process is inspiration. When the diaphragm isrelaxed, the volume of the thoracic cavity decreases, which in turndecreases the volume of the lungs. As the volume of the lungs decrease,the pressure of the air in the lungs rises slightly above the pressureof the air external to the body. Accordingly, as a result of this slightpressure differential, the air in the alveoli is expelled through therespiratory passageways until the pressure equalizes. This process isexpiration.

Continued insult to the respiratory system may result in variousdiseases, for example, chronic obstructive pulmonary disease. Chronicobstructive pulmonary disease is a persistent obstruction of the airwayscaused by chronic bronchitis and pulmonary emphysema. In the UnitedStates alone, approximately fourteen million people suffer from someform of chronic obstructive pulmonary disease and it is in the top tenleading causes of death.

Chronic bronchitis and acute bronchitis share certain similarcharacteristics; however, they are distinct diseases. Both chronic andacute. bronchitis involve inflammation and constriction of the bronchialtubes and the bronchioles; however, acute bronchitis is generallyassociated with a viral and/or bacterial infection and its duration istypically much shorter than chronic bronchitis. In chronic bronchitis,the bronchial tubes secrete too much mucus as part of the body'sdefensive mechanisms to inhaled foreign substances. Mucus membranescomprising ciliated cells (hair like structures) line the trachea andbronchi. The ciliated cells or cilia continuously push or sweep themucus secreted from the mucus membranes in a direction away from thelungs and into the pharynx, where it is periodically swallowed. Thissweeping action of the cilia functions to keep foreign matter fromreaching the lungs. Foreign matter that is not filtered by the nose andlarynx, as described above, becomes trapped in the mucus and ispropelled by the cilia into the pharynx. When too much mucus issecreted, the ciliated cells may become damaged, leading to a decreasein the efficiency of the cilia to sweep the bronchial tubes and tracheaof the mucus containing the foreign matter. This in turn causes thebronchioles to become constricted and inflamed and the individualbecomes short of breath. In addition, the individual will develop achronic cough as a means of attempting to clear the airways of excessmucus.

Individuals who suffer from chronic bronchitis may develop pulmonaryemphysema. Pulmonary emphysema is a disease in which the alveoli walls,which are normally fairly rigid structures, are destroyed. Thedestruction of the alveoli walls is irreversible. Pulmonary emphysemamay be caused by a number of factors, including chronic bronchitis, longterm exposure to inhaled irritants, e.g. air pollution, which damage thecilia, enzyme deficiencies and other pathological conditions. Inpulmonary emphysema, the alveoli of the lungs lose their elasticity, andeventually the walls between adjacent alveoli are destroyed.Accordingly, as more and more alveoli walls are lost, the air exchange(oxygen and carbon dioxide) surface area of the lungs is reduced untilair exchange becomes seriously impaired. The combination of mucushypersecretion and dynamic airway compression are mechanisms of airflowlimitation in chronic obstructive pulmonary disease. Dynamic airwaycompression results from the loss of tethering forces exerted on theairway due to the reduction in lung tissue elasticity. Mucushypersecretion is described above with respect to bronchitis. In otherwords, the breakdown of lung tissue leads to the reduced ability of thelungs to recoil and the loss of radial support of the airways.Consequently, the loss of elastic recoil of the lung tissue contributesto the inability of individuals to exhale completely. The loss of radialsupport of the airways also allows a collapsing phenomenon to occurduring the expiratory phase of breathing. This collapsing phenomenonalso intensifies the inability for individuals to exhale completely. Asthe inability to exhale completely increases, residual volume in thelungs also increases. This then causes the lung to establish in ahyperinflated state where an individual can only take short shallowbreaths. Essentially, air is not effectively expelled and stale airaccumulates in the lungs. Once the stale air accumulates in the lungs,the individual is deprived of oxygen. There is no cure for pulmonaryemphysema, only various treatments, including exercise, drug therapy,such as bronchodilating agents, lung volume reduction surgery and longterm oxygen therapy.

As described above, long term oxygen therapy is widely accepted as thestandard treatment for hypoxia caused by chronic obstructive pulmonarydisease. Typically, oxygen therapy is prescribed using a nasal cannula.There are disadvantages associated with using the nasal cannula. Onedisadvantage associated with utilizing nasal cannula is the significantloss of oxygen between the cannula and the nose, which in turn equatesto more frequent changes in the oxygen source, or higher energyrequirements to generate more oxygen. Another disadvantage associatedwith utilizing nasal cannula is the fact that the cannulas may cause thenasal passages to become dry, cracked and sore.

Transtracheal oxygen therapy has become a viable alternative to longterm oxygen therapy. Transtracheal oxygen therapy delivers oxygendirectly to the lungs using a catheter that is placed through and downthe trachea. Due to the direct nature of the oxygen delivery, a numberof advantages are achieved. These advantages include lower oxygenrequirements due to greater efficiency, increased mobility, greaterexercise capability and improved self image.

The long term oxygen therapy system and method of the present inventionmay be utilized to deliver oxygen directly into the lung tissue in orderto optimize oxygen transfer efficiency in the lungs. In other words,improved efficiency may be achieved if oxygen were to be delivereddirectly into the alveolar tissue in the lungs. In emphysema, alveoliwalls are destroyed, thereby causing a decrease in air exchange surfacearea. As more alveoli walls are destroyed, collateral ventilationresistance is lowered. In other words, pulmonary emphysema causes anincrease in collateral ventilation and to a certain extent, chronicbronchitis also causes an increase in collateral ventilation.Essentially, in an emphysematous lung, the communicating flow of airbetween neighboring air sacs (alveoli), known as collateral ventilation,is much more prevalent as compared to a normal lung. Since air cannot beexpelled from the native airways due to the loss of tissue elasticrecoil and radial support of the airways (dynamic collapse duringexhalation), the increase in collateral ventilation does notsignificantly assist an individual in breathing. The individual developsdsypnea. Accordingly, if it can be determined where collateralventilation is occurring, then the diseased lung tissue may be isolatedand the oxygen delivered to this precise location or locations. Variousmethods may be utilized to determine the diseased tissue locations, forexample, computerized axial tomography or CAT scans, magnetic resonanceimaging or MRI, positron emission tomograph or PET, and/or standardX-ray imaging. Once the diseased tissue is located, pressurized oxygenmay be directly delivered to these diseased areas and more effectivelyand efficiently forced into the lung tissue for air exchange.

FIG. 1 illustrates a first exemplary long term oxygen therapy system100. The system 100 comprises an oxygen source 102, an oxygen carryingconduit 104 and a one-way valve 106. The oxygen source 102 may compriseany suitable device for supplying filtered oxygen under adjustablyregulated pressures and flow rates, including pressurized oxygen tanks,liquid oxygen reservoirs, oxygen concentrators and the associateddevices for controlling pressure and flow rate e.g. regulators. Theoxygen carrying conduit 104 may comprise any suitable biocompatibletubing having a high resistance to damage caused by continuous oxygenexposure. The oxygen carrying conduit 104 comprises tubing having aninside diameter in the range from about 1/16 inch to about ½ inch andmore preferably from about ⅛ inch to about ¼ inch. The one-way valve 106may comprise any suitable, in-line mechanical valve which allows oxygento flow into the lungs 108 through the oxygen carrying conduit 104, butnot from the lungs 108 back into the oxygen source 102. For example, asimple check valve may be utilized. As illustrated in FIG. 1, the oxygencarrying conduit 104 passes through the lung 108 at the site determinedto have the highest degree of collateral ventilation.

The exemplary system 100 described above may be modified in a number ofways, including the use of an in-line filter. In this exemplaryembodiment, both oxygen and air may flow through the system. In otherwords, during inhalation, oxygen is delivered to the lungs through theoxygen carrying conduit 104 and during exhalation, air from the lungsflow through the oxygen carrying conduit 104. The in-line filter wouldtrap mucus and other contaminants, thereby preventing a blockage in theoxygen source 102. In this exemplary embodiment, no valve 106 would beutilized. The flow of oxygen into the lungs and the flow of air from thelungs is based on pressure differentials.

In order for the exemplary long term oxygen therapy system 100 tofunction, an airtight seal is preferably maintained where the oxygencarrying conduit 104 passes through the thoracic cavity and lung. Thisseal is maintained in order to sustain the inflation/functionality ofthe lungs. If the seal is breached, air can enter the cavity and causethe lungs to collapse as described above.

A method to create this seal comprises forming adhesions between thevisceral pleura of the lung and the inner wall of the thoracic cavity.This may be achieved using either chemical methods, including irritantssuch as Doxycycline and/or Bleomycin, surgical methods, includingpleurectomy or horoscope talc pleurodesis, or radiotherapy methods,including radioactive gold or external radiation. All of these methodsare known in the relevant art for creating pleurodesis. With a sealcreated at the site for the ventilation bypass, an intervention may besafely performed without the danger of creating a pneumothorax of thelung.

Similarly to ostomy pouches or bags, the oxygen carrying conduit 104 maybe sealed to the skin at the site of the ventilation bypass. In oneexemplary embodiment, illustrated in FIG. 2, the oxygen carrying conduit104 may be sealed to the skin of the thoracic wall utilizing anadhesive. As illustrated, the oxygen carrying conduit 104 comprises aflange 200 having a biocompatible adhesive coating on the skincontacting surface. The biocompatible adhesive would provide a fluidtight seal between the flange 200 and the skin or epidermis of thethoracic wall. In a preferred embodiment, the biocompatible adhesiveprovides a temporary fluid tight seal such that the oxygen carryingconduit 104 may be disconnected from the ventilation bypass site. Thiswould allow for the site to be cleaned and for the long term oxygentherapy system 100 to undergo periodic maintenance.

FIG. 3 illustrates another exemplary embodiment for sealing the oxygencarrying conduit 104 to the skin of the thoracic wall at the site of theventilation bypass. In this exemplary embodiment, a coupling plate 300is sealed to the skin at the site of the ventilation bypass by abiocompatible adhesive coating or any other suitable means. The oxygencarrying conduit 104 is then connected to the coupling plate 300 by anysuitable means, including threaded couplings and locking rings. Theexemplary embodiment also allows for cleaning of the site andmaintenance of the system 100.

FIG. 4 illustrates yet another exemplary embodiment for sealing theoxygen carrying conduit 104 to the skin of the thoracic wall at the siteof the ventilation bypass. In this exemplary embodiment, balloon flanges400 may be utilized to create the seal. The balloon flanges 400 may beattached to the oxygen carrying conduit 104 such that in the deflatedstate, the oxygen carrying conduit 104 and one of the balloon flangespasses through the ventilation bypass anastomosis. The balloon flanges400 are spaced apart a sufficient distance such that the balloon flangesremain on opposite sides of the thoracic wall. When inflated, theballoons expand and form a fluid tight seal by sandwiching the thoracicwall. Once again, this exemplary embodiment allows for easy removal ofthe oxygen carrying conduit 104.

FIG. 5 illustrates yet another exemplary embodiment for sealing theoxygen carrying conduit 104 to the skin of the thoracic wall at the siteof the ventilation bypass. In this exemplary embodiment, a singleballoon flange 500 is utilized in combination with a fixed flange 502.The balloon flange 500 is connected to the oxygen carrying conduit 104in the same manner as described above. In this exemplary embodiment, theballoon flange 500, when inflated, forms the fluid tight seal. The fixedflange 502, which is maintained against the skin of the thoracic wall,provides the structural support against which the balloon exertspressure to form the seal.

If an individual has difficulty exhaling and requires additional oxygen,collateral ventilation bypass may be combined with direct oxygentherapy. FIG. 6 illustrates an exemplary embodiment of a collateralventilation bypass/direct oxygen therapy system 600. The system 600comprises an oxygen source 602, an oxygen carrying conduit 604 havingtwo branches 606 and 608, and a control valve 610. The oxygen source 602and oxygen carrying conduit 604 may comprise components similar to theabove-described exemplary embodiment illustrated in FIG. 1. In thisexemplary embodiment, when the individual inhales, the valve 610 is openand oxygen flows into the lung 612 and into the bronchial tube 614. Inan alternate exemplary embodiment, the branch 608 may be connected tothe trachea 616. Accordingly, during inhalation oxygen flows to thediseased site in the lung or lungs and to other parts of the lungthrough the normal bronchial passages. During exhalation, the valve 610is closed so that no oxygen is delivered and air in the diseased portionof the lung may flow from the lung 612, through one branch 606 and intothe second branch 608 and finally into the bronchial tube 616. In thismanner, stale air is removed and oxygen is directly delivered. Onceagain, as described above, the flow of oxygen and air is regulated bysimple pressure differentials.

The connection and sealing of the oxygen carrying conduit 604 andbranches 606, 608 to the lung 612 and bronchial tube 614 may be made ina manner similar to that described above.

The above-described long term oxygen therapy system may be utilized toeffectively treat hypoxia caused by chronic obstructive pulmonarydisease; however, other means may be desirable to treat other aspects ofthe disease. As set forth above, emphysema is distinguished asirreversible damage to lung tissue. The breakdown of lung tissue leadsto the reduced ability for the lungs to recoil. The tissue breakdownalso leads to the loss of radial support of the native airways.Consequently, the loss of elastic recoil of the lung tissue contributesto the inability for individuals with emphysema to exhale completely.The loss of radial support of the native airways also allows acollapsing phenomenon to occur during the expiratory phase of breathing.This collapsing phenomenon also intensifies the inability forindividuals to exhale completely. As the inability to exhale increases,residual volume in the lungs also increases. This then causes the lungto establish in a hyperinflated state wherein an individual can onlytake short shallow breaths.

The collateral ventilation bypass trap system of the present inventionutilizes the above-described collateral ventilation phenomenon toincrease the expiratory flow from a diseased lung or lungs, therebytreating another aspect of chronic obstructive pulmonary disease.Essentially, the most collaterally ventilated area of the lung or lungsis determined utilizing the scanning techniques described above. Oncethis area or areas are located, a conduit or conduits are positioned ina passage or passages that access the outer pleural layer of thediseased lung or lungs. The conduit or conduits utilize the collateralventilation of the lung or lungs and allows the entrapped air to bypassthe native airways and be expelled to a containment system outside ofthe body.

FIG. 7 illustrates a first exemplary collateral ventilation bypass trapsystem 700. The system 700 comprises a trap 702, an air carrying conduit704 and a filter/one-way valve 706. The air carrying conduit 704 createsa fluid communication between an individual's lung 708 and the trap 702through the filter/one-way valve 706. It is important to note thatalthough a single conduit 704 is illustrated, multiple conduits may beutilized in each lung 708 if it is determined that there is more thanone area of high collateral ventilation.

The trap 702 may comprise any suitable device for collecting dischargefrom the individual's lung or lungs 708. Essentially, the trap 702 issimply a containment vessel for temporarily storing discharge from thelungs, for example, mucous and other fluids that may accumulate in thelungs. The trap 702 may comprise any suitable shape and may be formedfrom any suitable metallic or non-metallic materials. Preferably, thetrap 702 should be formed from a lightweight, non-corrosive material. Inaddition, the trap 702 should be designed in such a manner as to allowfor effective and efficient cleaning. In one exemplary embodiment, thetrap 702 may comprise disposable liners that may be removed when thetrap 702 is full. The trap 702 may be formed from a transparent materialor comprise an indicator window so that it may be easily determined whenthe trap 702 should be emptied or cleaned. A lightweight trap 702increases the patient's mobility.

The filter/one-way valve 706 may be attached to the trap 702 by anysuitable means, including threaded fittings or compression type fittingscommonly utilized in compressor connections. The filter/one-way valve706 serves a number of functions. The filter/one-way valve 706 allowsthe air from the individual's lung or lungs 708 to exit the trap 702while maintaining the fluid discharge and solid particulate matter inthe trap 702. This filter/one-way valve 706 would essentially maintainthe pressure in the trap 702 below that of the pressure inside theindividual's lung or lungs 708 so that the flow of air from the lungs708 to the trap 702 is maintained in this one direction. The filterportion of the filter/one-way valve 706 may be designed to captureparticulate matter of a particular size which is suspended in the air,but allows the clean air to pass therethrough and be vented to theambient environment. The filter portion may also be designed in such amanner as to reduce the moisture content of the exhaled air.

The air carrying conduit 704 connects the trap 702 to the lung or lungs708 of the patient through the filter/one-way valve 706. The aircarrying conduit 704 may comprise any suitable biocompatible tubinghaving a resistance to the gases contained in air. The air carryingconduit 704 comprises tubing having an inside diameter in the range fromabout 1/16 inch to about ½ inch, and more preferably from about ⅛ inchto about ¼ inch. The filter/one-way valve 706 may comprise any suitablevalve which allows air to flow from the lung or lungs 708 through theair carrying conduit 704, but not from the trap 702 back to the lungs708. For example, a simple check valve may be utilized. The air carryingconduit 704 may be connected to the filter/one-way valve 706 by anysuitable means. Preferably, a quick release mechanism is utilized sothat the trap may be easily removed for maintenance. As illustrated inFIG. 7, the air carrying conduit 704 passes through the lung 708 at thesite determined to have the highest degree of collateral ventilation. Ifmore than one site is determined, multiple air carrying conduits 704 maybe utilized. The connection of multiple air carrying conduits 704 to thefilter/one-way valve 706 may be accomplished by any suitable means,including an octopus device similar to that utilized in scuba divingregulators.

The air carrying conduit 704 is preferably able to withstand and resistcollapsing once in place. Since air will travel through the conduit 704,if the conduit is crushed and unable to recover, the effectiveness ofthe system is diminished. Accordingly, a crush recoverable material maybe incorporated into the air carrying conduit 704 in order to make itcrush recoverable. Any number of suitable materials may be utilized. Forexample, Nitinol incorporated into the conduit 704 will give the conduitcollapse resistance and collapse recovery properties.

Expandable features at the end of the conduit 704 may be used to aid inmaintaining contact and sealing the conduit 704 to the lung pleura.Nitinol incorporated into the conduit 704 will provide the ability todeliver the conduit 704 in a compressed state and then deployed in anexpanded state to secure it in place. Shoulders at the end of theconduit may also provide a mechanical stop for insertion and an area foran adhesive/sealant to join as described in detail subsequently.

In order for the exemplary collateral ventilation bypass trap system 700to function, an airtight seal is preferably maintained where the aircarrying conduit 704 passes through the thoracic cavity and lungs 708.This seal is maintained in order to sustain the inflation/functionalityof the lungs. If the seal is breached, air can enter the cavity andcause the lungs to collapse. One exemplary method for creating the sealcomprises forming adhesions between the visceral pleura of the lung andthe inner wall of the thoracic cavity. This may be achieved using eitherchemical methods, including irritants such as Doxycycline and/orBleomycin, surgical methods, including pleurectomy or thorascopic talcpleurodesis, or radiotherapy methods, including radioactive gold orexternal radiation. All of these methods are known in the relevant artfor creating pleurodesis. In another alternate exemplary embodiment, asealed joint between the air carrying conduit 704 and the outer pleurallayer includes using various glues to help with the adhesion/sealing ofthe air carrying conduit 704. Currently, Focal Inc. markets a sealantavailable under the tradename Focal/Seal-L which is indicated for use ona lung for sealing purposes. Focal/Seal-L is activated by light in orderto cure the sealant. Another seal available under the tradename Thorex,which is manufactured by Surgical Sealants Inc., is currently conductinga clinical trial for lung sealing indications. Thorex is a two-partsealant that has a set curing time after the two parts are mixed.

The creation of the opening in the chest cavity may be accomplished in anumber of ways. For example, the procedure may be accomplished using anopen chest procedure, aternotomy or thoracotomy. Alternately, theprocedure may be accomplished using a laproscopic technique, which isless invasive. Regardless of the procedure utilized, the seal should beestablished while the lung is at least partially inflated in order tomaintain a solid adhesive surface. The opening may then be made afterthe joint has been adequately created between the conduit component andthe lung pleural surface. The opening should be adequate incross-sectional area in order to provide sufficient decompression of thehyperinflated lung. This opening, as stated above, may be created usinga number of different techniques such as cutting, piercing, dilating,blunt dissection, radio frequency energy, ultrasonic energy, microwaveenergy, or cryoblative energy.

The air carrying conduit 704 may be sealed to the skin at the site byany of the means and methods described above with respect to the oxygencarrying conduit 704 and illustrated in FIGS. 2 through 5.

In operation, when an individual exhales, the pressure in the lungs isgreater than the pressure in the trap 702. Accordingly, the air in thehighly collaterilized areas of the lung will travel through the aircarrying conduit 704 to the trap 702. This operation will allow theindividual to more easily and completely exhale.

FIG. 8 illustrates another exemplary collateral ventilation bypasssystem 800. In this exemplary embodiment, the trachea is utilized toremove trapped air rather than the native airways. As illustrated, afirst conduit 802 extends from the patient's trachea 804, or otherproximal airways, including the bronchus, to a position external of thepatient's body. A second conduit 806 is connected to the first conduit802 via a fitting 808 and passes through the thoracic wall 810 andpasses through the lung 812 at the site determined to have the highestdegree of collateral ventilation. If more than one site is determined tohave a high degree of collateral ventilation, multiple conduits may beutilized. In operation, when the patient exhales, the pressure in thelungs is greater than the pressure in the trachea 804; accordingly, theair in the highly collateralized areas of the lung will travel throughthe first and second conduits 802, 806 to the trachea 804 and out of thepatient's nose and mouth with the normally exhaled air.

The first and second conduits 802, 806 may comprise any suitablebiocompatible tubing having a resistance to the various gases and otherconstituents contained in inhaled and exhaled air. As in previouslydescribed embodiments, the first and second conduits 802, 806 comprisetubing having an inside diameter in the range from about 1/16 inch toabout ½ inch, and more preferably from about ⅛ inch to about ¼ inch.

The connection of the first conduit 802 to the trachea 804 may compriseany suitable airtight seal. For example, a fluid communication betweenthe trachea 804 and the first conduit 802 may be established in a manneridentical to that established for a tracheotomy. In addition, as statedabove, in order for the collateral ventilation bypass system 800 tofunction, an airtight seal is preferably maintained where the secondconduit 806 passes through the thoracic wall 810 and into the lungs 812.An exemplary method for creating this airtight seal comprises formingadhesions between the visceral pleura of the lung and the parietalpleura. This may be achieved using either chemical methods, includingirritants, surgical methods, including pleurectomy or thorascopic talcpleurodesis, or radiotherapy methods, including radioactive gold orexternal radiation.

The creation of the opening in the thoracic wall may be accomplished ina number of ways. For example, the procedure may be accomplished usingan open chest procedure, aternotomy or thoracotomy. Alternately, theprocedure may be accomplished using a laproscopic technique, which isless invasive. Regardless of the procedure utilized, the seal should beestablished while the lung is at least partially inflated in order tomaintain a solid adhesive surface. The opening may then be made afterthe joint has been adequately created between the conduit component andthe lung pleural surface. The opening should be adequate incross-sectional area in order to provide sufficient decompression of thehyperinflated lung. This opening, as stated above, may be created usinga number of different techniques such as cutting, piercing, dilating,blunt dissection, radio frequency energy, ultrasonic energy, microwaveenergy, or cryoblative energy.

The conduits 802, 806 may be sealed to the skin at the sites by anyknown methods, including those described above with respect to FIGS. 2through 5. The connection of the extrathoracic component, conduit 806,may comprise a drug, chemical, agent, or other means for preventing orsubstantially reducing the risk of infection.

The fitting 808 connecting the first and second conduits 802, 806 maycomprise any suitable device for creating an airtight seal The fitting808 may comprise any type of threaded or non-threaded union, compressionfittings similar to compressor type fittings or any other suitabledevice for establishing an airtight seal and providing for quick releasebetween the two ends of the fitting 808. This type of design would alloweasy access for periodic maintenance of the system 800, for example,cleaning the conduits 802, 806. Since the fitting 808 is external to thebody, access to the inner body component of the system 800 would beeasier. Essentially, access of the system 800 from outside the bodywould allow for maintenance and diagnosis/observation of the system 800without subjecting the patient to additional stress and risk. It wouldalso be less time consuming for the doctor.

FIG. 9 illustrates an alternate exemplary embodiment of the exemplarycollateral ventilation bypass system 800 described above. In thisexemplary embodiment, the system 900 comprises an externally positionedaccess port 908. As illustrated, a conduit 902 extends from thepatient's trachea 904, or other proximal airways, including thebronchus, through a suitable passageway internal to the patient's bodyand then passes through the lung 912 at the site determined to have thehighest degree of collateral ventilation. As set forth above, if morethan one site is determined to have a high degree of collateralventilation, multiple conduits may be utilized. At the desired locationwithin the body, the access port 908 may be placed in-line with theconduit 902 such that at least a portion of the access port 908 isaccessible outside of the body. Essentially, the access port 908 shouldallow the patient or a doctor to open the port and access the system 900within the patient's body for maintenance and diagnosis/observation ofthe system 900 as described above.

The access port 908 may comprise any suitable device for providing anairtight seal when closed and easy access to the conduit 902 when open.The access port 908 may comprise various valve arrangements andconnectors for connecting other components which may be utilized forvarious functions. For example, oxygen may be supplied directly to thepatient's lungs 912 if needed. In this instance, a valve may be neededto prevent the oxygen from bypassing the lungs 912 and go straight tothe trachea 904.

All the remaining components may be the same as described above. Inaddition, all seals may be accomplished as described above.

In yet another alternate exemplary embodiment, the extrathoracic accessport 908, illustrated in FIG. 9, may be positioned just under the skinso that it is accessible percutaneously. Essentially, the access portwould not truly be extrathoracic, but rather just located under the skinand accessible extrathoracically. In this exemplary embodiment accesswould not be as easily accessible; however, the access point wouldremain more discrete than the previously described exemplaryembodiments. FIG. 10 illustrates this exemplary embodiment.

As illustrated in FIG. 10, the collateral ventilation bypass system 1000comprises a conduit 1002 that extends from the patient's trachea 1004,or other proximal airways, including the bronchus, through a suitablepassageway internal to the patient's body and then passes through thelung 1012 at the site determined to have the highest degree ofcollateral ventilation. As set forth above, if more than one site isdetermined to have a high degree of collateral ventilation, multipleconduits may be utilized. At the desired location within the body, aninternal access port 1008 may be placed in-line with the conduit 1002.The access port 1008 may comprise any suitable device that allows accessvia percutaneous means. All remaining components may be the same asdescribed above. In addition, all seals may be accomplished as describedabove.

It is important to note that in each of the above-described exemplaryembodiments, additional components may be added that function to preventflow from the trachea end of the conduit to the lung. For example, oneor more valves may be incorporated throughout the systems to preventmucus and other substances from entering or re-entering the lung. Themain function of the system is to allow exhalation. In theory, patientswith emphysema have increased resistance to expiration and notinhalation. Any suitable valves may be utilized, for example, one-waycheck valves.

As described above, pulmonary emphysema leads to the breakdown of lungtissue, which in turn leads to the reduced ability of the lungs torecoil and the loss of radial support of the airways. Consequently, theloss of elastic recoil of the lung tissue contributes to the inabilityof individuals to exhale completely. The loss of radial support of theairways also allows a collapsing phenomenon to occur during theexpiratory phase of breathing. This collapsing phenomenon alsointensifies the inability for individuals to exhale completely. As theinability to exhale completely increases, residual volume in the lungsalso increases. This then causes the lung or lungs to establish in ahyperinflated state where an individual can only take short shallowbreaths. Essentially, air is not effectively expelled and stale airaccumulates in the lungs. Once the stale air accumulates in the lungs,the individual is deprived of oxygen.

Lung volume reduction surgery is an extremely traumatic procedure thatinvolves removing part or parts of the lung or lungs. By removing theportion of the lung or lungs which is hyperinflated, pulmonary functionmay improve due to a number of mechanisms, including enhanced elasticrecoil, correction of ventilation/perfusion mismatch and improvedefficiency of respiratory work. Essentially, as the emphysematous tissuevolume is reduced, the healthier tissue is better ventilated. However,lung volume reduction surgery possesses a number of potential risks asdescribed in more detail subsequently.

The collateral ventilation bypass trap system 700, illustrated in FIG.7, and the collateral ventilation bypass system 800, illustrated in FIG.8, utilize the collateral ventilation phenomenon to allow the airentrapped in the lung or lungs to bypass the native airways and beexpelled either to a containment vessel or to the ambient environment.However, in an alternate exemplary embodiment, a device, which workssimilarly to collateral ventilation bypass and provides resultscommensurate with lung volume reduction surgery, is disclosed herein.Essentially, in this exemplary embodiment, the invention is directed toa device and associated method for assisting pulmonary decompression. Inother words, the present invention is directed to pulmonarydecompression assist device and method that would provide a means forthe removal of trapped air in the emphysematous lung and the maintenanceof the emphysematous area compressed to a smaller volume, with theresult being that healthier lung tissue will have more volume in thethoracic cavity to ventilate. The effects of this device may be similarto that of lung volume reduction surgery.

The exemplary pulmonary decompression assist device of the presentinvention may be strategically positioned in the body of a patient suchthat it is in fluid communication with the patient's lung or lungs andthe external environment. The device would allow air to be exhaled outfrom the lung or lungs through the native airways while assisting inremoving trapped air in the hyperinflated portion of the lung or lungs.Lung volume reduction surgery is an extremely invasive and traumaticprocedure that in a substantially high number of cases causes thepatients undergoing the procedure to become excluded from being acandidate for lung transplantation. The device of the present inventionprovides for a minimally invasive procedure for causing the lung volumeto reduce similarly to lung volume reduction surgery while allowing thepatient to remain a viable candidate for lung transplantation.

The exemplary pulmonary decompression device may utilize any number ofknown techniques for creating a sufficient pressure differential betweenthe inside of the lung or lungs and an area external of the lung orlungs to allow the trapped air to exit the lung or lungs. The device maycomprise any suitable device such as pumps or fans or any other means tocreate the pressure differential. If the collateral airflow and areas ofemphysema are situated so that air may reinflate that area, the devicemay be configured to continuously draw air from the lung or lungs tomaintain a smaller lung volume of the emphysematous tissue. The devicemay be left in the patient's body indefinitely in order to maintain thecompression of the emphysematous tissue in the lung or lungs. Inaddition, in order to maintain the cleanliness of the device and thesafety of the patient, the device may be constructed as a disposabledevice and be replaced at various intervals. In addition, portions ofthe device that are easily accessible may be made disposable.Alternately, the device may be constructed for easy removal, easycleaning and easy replacement.

Referring to FIG. 11, there is illustrated an exemplary pulmonarydecompression device 1100 in accordance with the present invention. Asdescribed herein, there is generally an optimal location to penetratethe outer pleura of the lung to access the most collaterally ventilatedarea or areas of the lung and a variety of techniques to locate the areaor areas. Once the desired location is determined, the decompressiondevice 1100 may be inserted into the lung 1102. On insertion andplacement of the decompression device 1100 into the lung 1102, it isparticularly advantageous to establish an airtight seal of the parietaland visceral pleurae. If a proper airtight seal is not created betweenthe decompression device, parietal and visceral pleurae, then apneumothorax may occur.

It is important to note that one or more devices may be utilized in eachlung to remove trapped air from highly collateralized areas.Alternately, a single device with multiple conduits may be utilized. Asillustrated in FIG. 11, the decompression device 1100 is placed in thelung 1102 in the area of highest collateral ventilation 1104. In oneexemplary embodiment, only a first section 1106 of the decompressiondevice 1100 is positioned within the lung 1102 while a second section1108 of the decompression device 1100 is secured external to the lung1102. The sealing of the device 1100 may be made in accordance with anyof the devices and methodologies described herein.

At least a portion of the second section 1108 is external to thepatient's body. The portion of the second section 1108 that is externalto the patient's body may exit the body at any suitable location. In oneexemplary embodiment, the portion of the second section 1108 exists thebody through the chest and thus may be sealed in accordance with any ofthe devices and methodologies described herein.

The first section 1106 may comprise any suitable biocompatible materialconfigured to facilitate the flow of air from the lung 1102. Forexample, the first section 1106 may comprise a conduit similar in size,material and construction as the other conduits described herein. Thesecond section 1108 may be connected to the first section 1106 by anysuitable means, including threaded unions or compression type fittings.The second section 1108 comprises a housing for an apparatus that drawsair from the hyperinflated portion of the lung 1104 through the firstsection 1106 and directs it out of the patient's body. The apparatus mayinclude any suitable device for creating a pressure differential betweenthe inside and outside of the lung 1102 such that air will easily flowfrom the lung 1102. The apparatus may include a miniature pump or fan.The miniature pump or fan may be powered by any suitable means,including batteries or rechargeable batteries. In the above-describedexemplary embodiment, the miniature pump or fan and its power supply maybe housed completely in the housing. In other alternate exemplaryembodiments, one or more of the pump/fan or power supply may be locatedremotely from the second section 1108. For example, the second section1108 may simply comprise a second conduit removably connected on one endto the first conduit and on a second end to the apparatus that draws airfrom the diseased section of the lung 1104.

In the exemplary embodiment illustrated in FIG. 11, the apparatus thatdraws air from the diseased section of the lung 1104 and its associatedpower supply are housed within the second section 1108. This designprovides the most freedom for the patient. Various known miniaturevacuum pumps or fans may be used to continuously draw air from thediseased section of the lung 1104, thereby reducing the emphysematoustissue volume and allowing the healthier tissue to ventilate better. Theminiature fan/pump and associated power supply may be separatecomponents or a single component. These miniature devices may comprisemicroelectromechanical systems or MEMS, or any other suitable device fordrawing air from one location and venting it to a second location. Thedecompression device 1100 should be designed to be easily maintained.For example, the second section 1108 may be made such that it can beremoved, the power supply recharged and the other components cleaned andthen replaced. Alternately, the second section 1108 may simply bedisposable.

The power supply may comprise any suitable means for supplying powercontinuously for extended periods of time. The power supply may comprisebatteries, rechargeable batteries, piezoelectric devices that generateelectrical power from mechanical strain or any other suitable device. Inaddition, other than a fan or pump for creating a vacuum, some type ofswitching elements may be utilized for creating a slight pressuredifferential.

Accordingly, rather than a resection of the lung tissue, thedecompression device removes trapped air from the emphysematous sectionof the lung and maintains the emphysematous section in a compressedstate or smaller volume, thereby allowing the healthier lung tissue morevolume in the thoracic cavity to ventilate. FIG. 12 a illustrates thedecompression device 1100 removing air from the hyperinflated portion1202 of the lung 1200. As illustrated, in this lung, the hyperinflatedor emphysematous portion 1202 of the lung 1200 is larger than thehealthy section or portion 1204 of the lung 1200. As the device 1100continues to remove the accumulated or trapped air, the volume of thehyperinflated portion 1202 of the lung 1200 shrinks, thereby allowingthe healthier portion 1204 more room to fully ventilate, therebyincreasing in volume as illustrated in FIG. 12 b.

In an alternate exemplary embodiment, a more passive device may beutilized for reducing the size of the lung. A lung reduction device maybe strategically positioned about the body of a patient and access thepatient's lung or lungs. The device would allow air to be expelled fromthe lung or lungs while preventing air from re-entering therethrough.Essentially, the device would comprise at least one component thataccesses the outer pleural layer of the emphysematous portion orportions of the patient's lung or lungs. This at least one componentwill utilize the collateral ventilation of the lung or lungs and allowthe entrapped air in the emphysematous portion or portions of the lungor lungs to bypass the native airways and expel through to the outsideof the body through a second component. The second component includes afeature that allows air to flow from the lung or lungs to the ambientenvironment, but not from the ambient environment back into the lung orlungs. If the collateral airflow and areas of emphysema are situated sothat air cannot reinflate these portions of the lung or lungs, then asize reduction of that area of the lung should occur.

Referring to FIGS. 13 a and 13 b, there is illustrated an exemplary lungreduction device 1300 in accordance with the present invention. Asdescribed herein, there is generally an optimal location to penetratethe outer pleura of the lung to access the most collaterally ventilatedarea or areas of the lung or lungs and a variety of techniques to locatethese areas. Once the desired location or locations are determined, thelung reduction device 1300 may be inserted into the lung 1302. Theinsertion or introduction of the device 1300 may be accomplishedutilizing a number of minimally invasive techniques, for example,percutaneously or endoscopically, thereby substantially reducing therisk to the patient and trauma to the lung or lungs. It is important tonote that all of the systems and devices described herein are preferablyimplanted utilizing minimally invasive techniques. On insertion andplacement of the lung reduction device 1300 into the lung 1302, it isparticularly advantageous to establish an airtight seal of the parietaland visceral pleurae utilizing any of the techniques, devices andprocesses described herein. If an airtight seal is not establishedbetween the lung reduction device 1300, parietal and visceral pleurae,then a pneumothorax may occur.

It is important to note that one or more lung reduction devices may beutilized in each lung to remove trapped air from highly collateralizedareas. Alternately, a single lung reduction device in fluidcommunication, through conduits or other similar means, with multiplelocations may be utilized. For case of explanation, a single device andsingle diseased portion is described and illustrated. Once again,referring to FIGS. 13 a and 13 b, the lung reduction device 1300 isimplanted in the lung 1302 in the area of highest collateral ventilation1304. In the exemplary embodiment illustrated, a first section 1306 ofthe lung reduction device 1300 is positioned within the inner volume ofthe lung 1302 while a second section 1308 of the lung reduction device1300 is secured to the patient's body external to the lung 1302. Thefirst section 1306 of the device 1300 accesses the parenchyma of thelung 1302. The parenchyma are the cells in tissues that are concernedwith function rather than structure. In other words, the first section1306 accesses the alveoli of the lung 1302. The attainment of anairtight seal of the lung reduction device 1300 may be made inaccordance with any of the devices and methodologies described herein.

At least a portion of the second section 1308 is external to thepatient's body. The portion of the second section 1308 that is externalto the patient's body may exit or extend from the body at any suitablelocation. Preferably, the portion of the second section 1308 exits at alocation that proves to be of minimum burden to the patient and allowsfor easy access for maintenance, repair or replacement. In one exemplaryembodiment, the portion of the second section 1308 exits the bodythrough the chest and thus may be sealed in accordance with any of thedevices and methodologies described herein.

The first section 1306 may comprise any suitable device for facilitatingthe flow of air from the lung 1302. For example, the first section 1306may comprise a conduit similar in size, material and construction or anyof the other conduits described herein. The second section 1308 may beconnected to the first section 1306 by any suitable means, includingthreaded connectors, unions or compression type fittings.

The second section 1308 may comprise any suitable means for allowingone-way airflow. In one exemplary embodiment, the second section 1308comprises a housing 1310 and a one-way valve 1312. The housing 1310 maybe formed from any suitable biocompatible material. A portion of thehousing 1310 houses the one-way valve 1312 while another portion of thehousing 1310 forms the portion that is external to the body. The one-wayvalve 1312 may comprise any suitable pressure actuated valve, whichallows air to flow from one lung 1302 to the ambient environment. Theone-way valve 1312 may comprise a check valve, a reed valve, needlevalves, flapper check valves or any other suitable device. In preferredembodiments, the one-way valve 1312 requires only a slight pressuredifferential to open and allow air flow from the lung 1302 to theambient or external environment, but does not allow air flow back intothe lung 1302 even under substantial reverse pressure.

In operation, when the person inhales, the volume of the thoracic cavityincreases by the contraction of the diaphragm and thus the volume of thelungs also increases. As the volume of the lungs increase, the pressureof the air in the lungs falls slightly below the pressure of the airexternal to the body and thus air flows through the respiratorypassageways into the lungs until the pressure equalizes. When the personexhales, the diaphragm is relaxed, the volume of the thoracic cavitydecreases, which in turn decreases the volume of the lungs. As thevolume of the lungs decrease, the pressure of the air in the lungs risesslightly above the pressure of the air external to the body.Accordingly, as a result of this slight pressure differential, the airin the alveoli is expelled through the respiratory passageways until thepressure equalizes. However, in the diseased area 1304 of the lung 1302,normal exhalation does not work for the reasons described herein andthus the increased pressure in the lung 1302 opens the one-way valve1312 and air flows from the diseased portion 1304 through the firstsection 1306, through the one-way valve 1312 and out of the body.

The lung reduction device 1300 may be left in the lung indefinitely tomaintain the compression of the emphysematous tissue lung 1300 asdescribed above with respect to the decompression device. In order tomaintain cleanliness and safety, the lung reduction device 1300 or atleast portions thereof may be made disposable and thus be replaced atregular intervals or when needed. As the lung reduction device 1300continues to allow the trapped air to exit the lung 1302, the volume ofthe hyperinflated or diseased portion 1304 of the lung 1300 shrinks,thereby allowing the healthier portion of the lung 1300 more room tofully ventilate, thereby increasing in volume as illustrated in FIG. 13b.

The lung reduction device 1300 may be left in the body until the area ofthe compressed emphysematous tissue has permanently compressed,atelectasis. At this point, the lung reduction device 1300 maypotentially be removed safely. If healing of the insertion site of thereduction device 1300 has occurred, the fistula created may bepermanently sealed.

In the above-described exemplary apparatus and procedure for increasingexpiratory flow from a diseased lung using the phenomenon of collateralventilation, there will be an optimal location to penetrate the outerpleura of the lung to access the most collaterally ventilated area orareas of the lung. In addition, in the above-described exemplarypulmonary decompression assist device, there is an optimal location fordecompressing the hyperinflated lung or lungs. As described above, thereare a variety of techniques to locate the most collaterally ventilatedarea or areas of the lungs. Since a device or component of the apparatusfunctions to allow the air entrapped in the lung to bypass the nativeairways and be expelled outside of the body, it is particularlyadvantageous to provide an airtight seal of the parietal (thoracic wall)and visceral (lung) pleurae. If a proper airtight seal is not createdbetween the device, parietal and visceral pleurae, then a pneumothorax(collapsed lung) may occur. Essentially, in any circumstance where thelung is punctured and a device inserted, an airtight seal shouldpreferably be maintained.

One way to achieve an airtight seal is through pleurodesis, i.e. anobliteration of the pleural space. There are a number of pleurodesismethods, including chemical, surgical and radiological. In chemicalpleurodesis, an agent such as tetracycline, doxycycline, bleomycin ornitrogen mustard may be utilized. In surgical pleurodesis, a pleurectomyor a thorascopic talc procedure may be performed. In radiologicalprocedures, radioactive gold or external radiation may be utilized. Inthe present invention, chemical pleurodesis is utilized.

Exemplary devices and methods for delivering a chemical(s) or agent(s)in a localized manner for ensuring a proper airtight seal of theabove-described apparatus is described below. The chemical(s), agent(s)and/or Compound(s) are used to create a pleurodesis between the parietaland visceral pleura so that a component of the apparatus may penetratethrough the particular area and not result in a pneumothorax. There area number of chemical(s), agent(s) and/or compound(s) that may beutilized to create a pleurodesis in the pleural space. The chemical(s),agent(s) and/or compound(s) include talc, tetracycline, doxycycline,bleomycin and minocycline.

In one exemplary embodiment, a modified drug delivery catheter may beutilized to deliver chemical(s), agent(s) and/or compound(s) to alocalized area for creating a pleurodesis in that area. In thisexemplary embodiment, the pleurodesis is formed and then the conduit704, as illustrated in FIG. 7, is positioned in the lung 708 through thearea of the pleurodesis. The drug delivery catheter provides a minimallyinvasive means for creating a localized pleurodesis. Referring to FIG.14, there is illustrated an exemplary embodiment of a drug deliverycatheter that may be utilized in accordance with the present invention.Any number of drug delivery catheters may be utilized. In addition, thedistal tip of the catheter may comprise any suitable size, shape orconfiguration thereby enabling the formation of a pleurodesis having anysize, shape or configuration.

As illustrated in FIG. 14, the catheter 1400 is inserted into thepatient such that the distal end 1402 is positioned in the pleural space1404 between the thoracic wall 1408 and the lung 1406. In theillustrated exemplary embodiment, the distal end 1402 of the catheter1400 comprises a substantially circular shape that would allow thechemical(s), agent(s) and/or compound(s) to be released towards theinner diameter of the substantially circular shape as indicated byarrows 1410. The distal end 1402 of the catheter 1400 comprising aplurality of holes or openings 1412 through which the chemical(s),agent(s) and/or compound(s) are released. As stated above, the distalend 1402 may comprise any suitable size, shape or configuration. Oncethe chemical(s), agent(s) and/or compound(s) are delivered, the catheter1400 may be removed to allow for implantation of the conduit 704 (FIG.7). Alternately, the catheter 1400 may be utilized to facilitatedelivery of the conduit 704.

The distal end or tip 1402 of the catheter 1400 should preferablymaintain its desired size, shape and/or configuration once deployed inthe pleural space. This may be accomplished in a number of ways. Forexample, the material forming the distal end 1402 of the catheter 1400may be selected such that it has a certain degree of flexibility forinsertion of the catheter 800 and a certain degree of shape memory suchthat it resumes its original or programmed shape once deployed. Anynumber of biocompatible polymers with these properties may be utilized.In an alternate embodiment, another material may be utilized. Forexample, a metallic material having shape memory characteristics may beintegrated into the distal end 1402 of the catheter 1400. This metallicmaterial may include nitinol or stainless steel. In addition, themetallic material may be radiopaque or comprise radiopaque markers. Byhaving a radiopaque material or radiopaque markers, the catheter 1400may be viewed under x-ray fluoroscopy and aid in determining when thecatheter 1400 is at the location of the highest collateral ventilation.

In another alternate exemplary embodiment, a local drug delivery devicemay be utilized to deliver the pleurodesis chemical(s), agent(s) and/orcompound(s). In this exemplary embodiment, the pleurodesis is formed andthen the conduit 704, as illustrated in FIG. 7, is positioned in thelung 708 through the pleurodesis. In this exemplary embodiment,chemical(s), agent(s) and/or compound(s) may be affixed to animplantable medical device. The medical device is then implanted in thepleural cavity at a particular site and the chemical(s), agent(s) and/orcompound(s) are released therefrom to form or create the pleurodesis.

Any of the above-described chemical(s), agent(s) and/or compound(s) maybe affixed to the medical device. The chemical(s), agent(s) and/orcompound(s) may be affixed to the medical device in any suitable manner.For example, the chemical(s), agent(s) and/or compound(s) may be coatedon the device utilizing any number of well known techniques including,spin coating, spraying or dipping, they may be incorporated into apolymeric matrix that is affixed to the surface of the medical device,they may be impregnated into the outer surface of the medical device,they may be incorporated into holes or chambers in the medical device,they may be coated onto the surface of the medical device and thencoated with a polymeric layer that acts as a diffusion barrier forcontrolled release of the chemical(s), agent(s) and/or compound(s), theymay be incorporated directly into the material forming the medicaldevice, or any combination of the above-described techniques. In anotheralternate embodiment, the medical device may be formed from abiodegradable material which elutes the chemical(s), agent(s) and/orcompound(s) as the device degrades.

The implantable medical device may comprise any suitable size, shapeand/or configuration, and may be formed using any suitable biocompatiblematerial. FIG. 15 illustrates one exemplary embodiment of an implantablemedical device 1500. In this embodiment, the implantable medical device1500 comprises a substantially cylindrical disk 1500. The disk 1500 ispositioned in the pleural space 1502 between the thoracic wall 1504 andthe lung 1506. Once in position, the disk 1500 elutes or otherwisereleases the chemical(s), agent(s) and/or compound(s) that form thepleurodesis. The release rate may be precisely controlled by using anyof the various techniques described above, for example, a polymericdiffusion barrier. Also, as stated above, the disk 1500 may be formedfrom a biodegradable material that elutes the chemical(s), agent(s)and/or compound(s) as the disk 1500 itself disintegrates or dissolves.Depending upon the material utilized in the construction of the disk1500, a non-biodegradable disk 1200 may or may not require removal fromthe pleural cavity 1502 once the pleurodesis is formed. For example, itmay be desirable that the disk 1500 is a permanent implant that becomesintegral with the pleurodesis.

As described in the previous exemplary embodiment, the disk 1500 maycomprise a radiopaque marker or be formed from a radiopaque material.The radiopaque marker or material allows the disk 1500 to be seen underfluoroscopy and then positioned accurately.

In yet another alternate exemplary embodiment, the fluid characteristicsof the chemical(s), agent(s) and/or compound(s) may be altered. Forexample, the chemical(s), agent(s) and/or compound(s) may be made moreviscous. With a more viscous chemical agent and/or compound, there wouldbe less chance of the chemical, agent and/or compound moving from thedesired location in the pleural space. The chemical(s), agent(s) and/orcompound(s) may also comprise radiopaque constituents. Making thechemical(s), agent(s) and/or compounds radiopaque would allow theconfirmation of the location of the chemical(s), agent(s) and/orcompound(s) with regard to the optimal location of collateralventilation.

The chemical(s), agent(s) and/or compound(s) as modified above may beutilized in conjunction with standard chemical pleurodesis devices andprocesses or in conjunction with the exemplary embodiments set forthabove.

Although shown and described is what is believed to be the mostpractical and preferred embodiments, it is apparent that departures fromspecific designs and methods described and shown will suggest themselvesto those skilled in the art and may be used without departing from thespirit and scope of the invention. The present invention is notrestricted to the particular constructions described and illustrated,but should be constructed to cohere with all modifications that may fallwithin the scope of the appended claims.

1. A method for reducing the volume of a hyperinflated portion of a lungof a patient comprising: determining a site of hyprinflation in apatient's lung; allowing air from the hyperinflated portion of the lungto vent through a device to the ambient environment; and wherein theallowing step includes: a. positioning a sealing device to establish anairtight seal between at least one first implantable member and thelung; and b. positioning the at least the one first implantable memberin fluid communication, at the predetermined site, within a lung of apatient, the at least one implantable member passing through a lung viaa passage created therethrough; and c. positioning a second memberconnected to the at least one first implantable member, the secondmember being secured external of the lung.
 2. A method for reducing thevolume of a hyperinflated portion of a lung of a patent comprising:determining a site of hyperinflation in a patient's lung; allowing airfrom the hyperinflated portion of the lung to vent through a device tothe ambient environment; and wherein the allowing step includes: a.positioning a first sealing device to establish an airtight seal betweenat least one first member and the lung; b. positioning the at least onefirst implantable member in fluid communication, at the predeterminedsite, within a lung of a patient, the at least one implantable memberpassing through a lung via a passage created therethrough; C.positioning a second member connected to and in fluid communication withthe at least one first implantable member, the second member allows airfrom the lung of the patient to vent to the ambient environment, thesecond member positioned external of the body of the patient; and d.positioning a second sealing device to seal the second member to thebody.